Experimental Verification for Active Power Filter based Four-Leg Inverter with SUI-PI Controller

Four-leg active power filter (4-LAPF) is considered one of the vital active filters that are frequently used in industrial applications, especially those that need to be controlled in each phase. In addition to control the neutral current that is created because of unbalanced and non-linear loads. In this paper, the active filter is controlled by a proposed control method that can achieve simplicity and intelligence at the same time. The novelty of this paper is simulation and experimental verification for the proposed controller with 4-LAPF. This controller relies on instantaneous reactive power theory, which is used to create the reference currents for the 4-LAPF to inject into the network to mitigate problems associated with unbalanced and non-linear loads. As a result, the supply current is maintained a pure sinusoidal wave. The system is simulated using Matlab/Simulink and experimentally verified. The simulation and experimental results prove the preference of the proposed controller over the conventional proportional-integration controller, where it reduces the total harmonic distortion of the supply current and enhance the power quality.